Optical film and display device including the same

Abstract

An optical film comprises a polarizing layer, a first optical compensation layer that is disposed under the polarizing layer and is a biaxial plate, a second optical compensation layer that is disposed under the first optical compensation layer and is a quarter wave plate, and a third optical compensation layer that is disposed under the second optical compensation layer and is a positive C plate. The first optical compensation layer has an optical axis angle of 86 to 94 degrees with respect to a transmission axis of the polarizing layer.

What is claimed is: 
     
         1 . An optical film, comprising:
 a polarizing layer;   a first optical compensation layer that is disposed under the polarizing layer and is a biaxial plate;   a second optical compensation layer that is disposed under the first optical compensation layer and is a quarter wave plate; and   a third optical compensation layer that is disposed under the second optical compensation layer and is a positive C plate,   wherein the first optical compensation layer has an optical axis angle of 86 to 94 degrees with respect to a transmission axis of the polarizing layer.   
     
     
         2 . The optical film of  claim 1 , wherein the first optical compensation layer has an in-plane retardation value (Ro) from 170 nm to 270 nm. 
     
     
         3 . The optical film of  claim 1 , wherein the first optical compensation layer has a refractive index ratio (Nz) from 0.5 to 2.5. 
     
     
         4 . The optical film of  claim 1 , wherein the first optical compensation layer has a retardation value (Rth) from 4 nm to 84 nm in a thickness direction. 
     
     
         5 . The optical film of  claim 1 , wherein the transmission axis of the polarizing layer is at 0 degrees and an optical axis of the second optical compensation layer is at 45 degrees. 
     
     
         6 . The optical film of  claim 1 , further comprising at least one of a first protective member disposed on the polarizing layer or a second protective member disposed between the polarizing layer and the first optical compensation layer. 
     
     
         7 . The optical film of  claim 6 , further comprising:
 a first adhesive member disposed between the first optical compensation layer and the second optical compensation layer; and   a second adhesive member disposed between the second optical compensation layer and the third optical compensation layer.   
     
     
         8 . The optical film of  claim 6 , wherein the second optical compensation layer is in contact with a bottom surface of the first optical compensation layer. 
     
     
         9 . The optical film of  claim 1 , wherein the first optical compensation layer is in contact with a bottom surface of the polarizing layer. 
     
     
         10 . A display device, comprising:
 a display panel; and   an optical film disposed on the display panel,   wherein the optical film includes:
 a polarizing layer; 
 a first optical compensation layer that is disposed under the polarizing layer and is a biaxial plate; 
 a second optical compensation layer that is disposed under the first optical compensation layer and is a quarter wave plate; and 
 a third optical compensation layer that is disposed under the second optical compensation layer and is a positive C plate, 
 wherein the first optical compensation layer has an optical axis angle of 86 to 94 degrees with respect to a transmission axis of the polarizing layer. 
   
     
     
         11 . The display device of  claim 10 , wherein the third optical compensation layer is closer to the display panel than the polarizing layer, and is in contact with the display panel. 
     
     
         12 . The display device of  claim 10 , further comprising:
 a cover window disposed in front of the optical film;   a polymer film layer disposed behind the display panel; and   a cushion layer disposed behind the polymer film layer.   
     
     
         13 . The display device of  claim 10 , wherein the first optical compensation layer has an in-plane retardation value (Ro) from 170 nm to 270 nm. 
     
     
         14 . The display device of  claim 10 , wherein the first optical compensation layer has a refractive index ratio (Nz) from 0.5 to 2.5. 
     
     
         15 . The display device of  claim 10 , wherein the first optical compensation layer has a retardation value (Rth) from 4 nm to 84 nm in a thickness direction. 
     
     
         16 . The display device of  claim 10 , wherein the transmission axis of the polarizing layer is at 0 degrees and an optical axis of the second optical compensation layer is at 45 degrees. 
     
     
         17 . The display device of  claim 10 , further comprising at least one of a first protective member disposed on the polarizing layer or a second protective member disposed between the polarizing layer and the first optical compensation layer. 
     
     
         18 . The display device of  claim 17 , further comprising:
 a first adhesive member disposed between the first optical compensation layer and the second optical compensation layer; and   a second adhesive member disposed between the second optical compensation layer and the third optical compensation layer.   
     
     
         19 . The display device of  claim 17 , wherein the second optical compensation layer is in contact with a bottom surface of the first optical compensation layer. 
     
     
         20 . An optical film, comprising:
 a polarizing layer;   a first optical compensation layer that is disposed under the polarizing layer and is a biaxial plate;   a second optical compensation layer that is disposed under the first optical compensation layer and is a quarter wave plate; and   a third optical compensation layer that is disposed under the second optical compensation layer and is a positive C plate,   wherein
 the first optical compensation layer has an in-plane retardation value (Ro) from 170 nm to 270 nm, 
 the first optical compensation layer has a refractive index ratio (Nz) from 0.5 to 2.5, and 
   the first optical compensation layer has a retardation value (Rth) from 4 nm to 84 nm in a thickness direction.